The Pierce Silver Stain Kit is a rapid, ultra-sensitive, and versatile silver stain system for protein detection in polyacrylamide gels, yielding consistent and reliable results. It is a metallic silver (Ag) protein stain that yields a remarkably clear and uniform gel background. In standard mini gels, proteins are detectable at greater than 0.25 ng per band or spot. The protocol has been optimized for flexibility by allowing short or overnight gel fixation and staining steps without affecting staining performance (sensitivity or clarity). A short (one-minute) sensitization step, performed after gel fixation, yields results that are free of the characteristically dark or blotchy backgrounds often seen with homemade or other commercially available silver stains. This feature is beneficial when performing densitometric analysis of silver stained gels.